It would use the gasoline engine during times of performance and during stop and go conditions.
But when the car was stopped and during normal cruising conditions the electric engine was used. This would cut down on the usage of gas and in some cases double the fuel mileage of the car. The car's battery would automatically be charged when the gas powered engine was on. This way it only needed one fuel source. But as the price of gas has risen even more, the need for a completely gas free car has come present. That is why the popularity for electric cars has risen. Many companies have conducted a lot of research on electric engines and have made them very reliable and efficient. Because of this, electric cars have become very fast and the distances they can travel have increased. The most notable showing of this would be when one of the fastest 0 to 60 cars, the Porsche 911, was beaten by an all-electric powered
car.